Showing posts with label Trans-Pacific. Show all posts
Showing posts with label Trans-Pacific. Show all posts

Saturday, December 31, 2022

12,000km+ opening on the 40 MHz band from California to Australia - 28th Dec 2022


Following on from the report of a 12,000km+ opening from South Africa to the United States, here is another report of remarkable opening on the 40 MHz band from California to Australia.

On the 28th of December 2022, Hilary VK2AZ in Sydney, Australia managed to get two decodes of the WSPR signal from Chris, WM2XCC in California on the 40 MHz (8m) band. The distance was 12,156 kms.

2022-12-28 01:36   WM2XCC   40.681491   -22   0   DM13ji   50   VK2AZ   QF56if   12156   242   2 
2022-12-28 01:28   WM2XCC   40.681492   -22   0   DM13ji   50   VK2AZ   QF56if   12156   242   2

Screenshot from VK2AZ

WM2XCC is the experimental callsign allocated by the FCC to Chris, N3IZN. For his experimental 8m WSPR transmissions, he was using 50-watts to a half-wave vertical.

VK2AZ in Sydney was using a horizontal half-wave dipole in a very noisy suburban location.

Analysis... At 01:30 UTC, the sun would have been over the centre of the Pacific Ocean so it's probably no great surprise that it happened at this time as the level of ionization would have been at maximum. With the solar flux now reaching 150-160, F2 trans-equatorial (north-south) paths up as high as 50 MHz are being reported recently.

In the last few weeks, there have been paths on the 50 MHz band from Australia & New Zealand to the western half of the United States. As 40 MHz is a lower band, it was likely that the path was open as well recently but this is the first time that an 8m signal across the Pacific has been reported.

In terms of propagation and potential paths, the 40 MHz band will never be as good as the 28 MHz band but it should always be better than 50 MHz. The reason it isn't obvious is just a lack of activity and reports.

Link...
1) For more info on the 8m band, visit my 40 MHz page

Wednesday, December 15, 2021

Trans-Pacific 50 MHz opening between New Zealand and South America - 14th Dec 2021


14th December 2021: It's interesting to see that long distance paths across the Pacific on the 50 MHz band are now beginning to get better in the southern hemisphere.

The map above shows some of the 6m signals heard by ZL1RS in New Zealand with paths to South America ranging from 9,836 kms to 12,595 kms.

 Txmtr Band Mode Distance Time (UTC)
PY4AQA 6m Q65 12595 km 22:30:30
PY2XB 6m Q65 12202 km 22:49:29
PU2MBY 6m Q65 12059 km 23:13:27
PY5EW 6m Q65 11967 km 23:33:27
PY5KD 6m Q65 11893 km 23:13:27
PT9FD 6m Q65 11825 km 23:08:29
LU5FF 6m Q65 10736 km 22:52:29
CE3VRT 6m Q65 9836 km 23:20:32

Note the mode... Q65! FT8 isn't the only weak signal mode.

The times are in UTC so in reality, this opening was during the daytime with the sun over the Pacific.

Propagation Mode??... As it's December, the Summer Sporadic-E season in the southern hemisphere has started and is likely to get better. 

If we assume the average Sporadic-E hop to be say 2000kms, did 5 or 6 of these hops line up for the 50 MHz signal to get from South America to New Zealand?

I'd be pretty certain that Sporadic-E was involved to some extent but I don't think anyone can say for certain it was 100% responsible. Was part of it chordal hop? Was the mesosphere region associated with noctilucent clouds involved?

As the openings get better, it'll be interesting to see the signals extend as far as Australia and what paths open up then.

Update from Bob, ZL1RS: Bob mentions that there have been several openings from ZL1 (North Island of New Zealand) to South America on 6m in the last few weeks.

25th Nov 2021 - CE (Chile) and PY (Brazil)
26th Nov 2021 - CE and LU (Argentina)
01st Dec 2021 - LU (RX only)
02nd Dec 2021 - CE
10th Dec 2021 - CE
14th Dec 2021 - as noted above

Bob adds... "... and on another date that I did not note, with propagation from ZL3 to SA.
... and signals from SA have been reported as received in VK3 and VK5 (while the operators were out of the shack). Having said that, the opening on 14 Dec was the most sustained so far this season ... signals in and out from 21:15 UTC until 23:15 UTC."